The present invention relates to a pneumatically suspended bus for route service.
The chief problem encountered in the design of buses to serve fixed routes is the need to minimize the boarding level above the roadway while maintaining the ground clearance needed for safe running operation and ensuring sufficient angles of slope. Although many attempts have been made to satisfy these two requirements the ideal solution is still wanting.
The prior art discloses a pneumatically suspended vehicle having a level control system where the height of the vehicle above the roadway is adjusted within limits by selective pressurization of the air suspension bellows, which in the case of a bus would enable it to be lowered at the bus stop.
Another solution has also been disclosed where the body of a pneumatically suspended bus is lowered to the road using a level control system. It has been shown, however, that in practice the lowering of the bodies of buses at stops by slective pressurization of an air suspension bellows fails to provide an entirely satisfactory solution, especially because periodic inflation of the air bellows consumes considerable amounts of energy. Also because inflation or deflation of the air bellows takes too long, and as a result, the advantage provided by the low boarding level and the resulting expedited boarding and deboarding rates is again cancelled by the disadvantage of longer stops at the bus stop. This is because of the need to lift the body of the bus again when the passengers have boarded.